package Tree;

/**
 * @Author: 吕庆龙
 * @Date: 2020/7/21 14:55
 * <p>
 * 功能描述:
 */
public class JZ_018 {

    public void Mirror(TreeNode root) {
        helper(root);
    }

    public TreeNode helper(TreeNode root){
        if(root == null)
            return null;
        TreeNode tmp = root.left;
        root.left = helper(root.right);
        root.right = helper(tmp);
        return root;
    }
}
